The nucleus can be considered a relativistic system, In particular, we focus on heavy nuclei with zero spin and utilize the relativistic core-cluster model to investigate their structure properties. A zero-spin nucleus is assumed to consist of a core and a cluster, core and cluster spins are zero. We will solve the Klein–Gordon equation, which is a relativistic equation optimized for studying zero-spin systems, with the new phenomenological potential. Then, we will calculate the binding energy and charge radius of the zero-spin heavy nuclei by employing the wave function obtained from the Klein–Gordon equation.